Re: [css-position] Sticky positioning computations

On 2014-03-06 18:03, Corey Ford wrote:
>> - Should the ReleasePosition be computed any differently if the ContainingBox is also the ScrollerBox?
> 
> My intuition is that in this case the ReleasePosition should be based on
> the size of the contents of the ScrollerBox (not its outer size).
> 
> WebKit appears to use the ScrollerBox's outer size, and Gecko currently
> ignores ReleasePosition entirely, but is investigating using the size of
> the scrolled contents:
> https://bugzilla.mozilla.org/show_bug.cgi?id=915302
> 
> (And supporting this case is certainly useful, e.g. sticky toolbars or
> sidebars, although often the ReleasePosition wouldn't matter there.)

Now I'm not sure which of those options makes more sense: not setting a
ReleasePosition, or computing it based on the size of the scrolled
contents as if there were an intervening wrapper <div>.
(I think WebKit's behavior doesn't, though.)

As I mentioned, setting a ReleasePosition in this situation might not be
useful very often, and authors would still have the option to add an
extra wrapper element to get the latter behavior.

Is "size of the scrolled contents" a sensible concept in CSS? Any other
opinions on this issue?

Corey